The switch to 20nm NAND flash memory should lead to lower cost drives.
OCZ announced a new 20nm NAND flash version of its popular Vertex 3 solid state drive (SSD) Series dubbed Vertex 3.20. Like the original, the Vertex 3.20 Series features a 6Gbps interface, multi-level cell (MLC) memory, and the same LSI SandForce SF-2200 controller. Performance specs are similar too, so why the switch? It all boils down to money, and in this case, 20nm has had time to mature and drop in price.
According to OCZ, the implementation of 20nm NAND flash will extend the Vertex 3's availabilty in the mainstream market. In theory, it should also cost consumers less, though OCZ didn't announce any pricing at this time.
Don't expect OCZ to swap out the chips in its higher end drives just yet. The reason why only the Vertex 3 line has been updated to 20nm parts is because the chips are slower than their 25nm counterparts, hence why the Vertex 4 and Vector lines won't be making the switch just yet.
It makes sense on the Vertex 3 Series because here's how performance shakes out compared to the original drives:
120GB Vertex 3.20 (20nm): 550MB/s read, 520MB/s write, 20K IOPS 4K random read, 40K IOPS random write
120GB Vertex 3 (25nm): 550MB/s read, 500MB/s write, 20K IOPS 4K random read, 60K IOPS random write
240GB Vertex 3.20 (20nm): 550MB/s read, 520MB/s write, 35K IOPS 4K random read, 65K IOPS random write
240GB Vertex 3 (25nm): 550MB/s read, 520MB/s write, 40K IOPS 4K random read, 60K IOPS random write
There's not much difference there, and in some cases, the 20nm version is actually faster than the 25nm model.